Tailoring the Techno-Functional Properties of Fava Bean Protein Isolates: A Comparative Evaluation of Ultrasonication and Pulsed Electric Field Treatments

The fava bean protein isolate (FBPI) holds promise as a sustainable plant-based protein ingredient. However, native FBPIs exhibit limited functionality, including unsuitable emulsifying activities and a low solubility at a neutral pH, restricting their applications. This study is focused on the effect of ultrasonication (US) and pulsed electric fields (PEF) on modulating the techno-functional properties of FBPIs. Native FBPIs were treated with US at amplitudes of 60-90% for 30 min in 0.5 s on-and-off cycles and with PEF at an electric field intensity of 1.5 kV/cm with 1000-4000 pulses of 20 μs pulse widths. US caused a reduction in the size and charge of the FBPIs more prominently than the PEF. Protein characterization by means of SDS-PAGE illustrated that US and PEF caused severe-to-moderate changes in the molecular weight of the FBPIs. In addition, a spectroscopic analysis using Fourier-transform infrared (FTIR) and circular dichroism (CD) revealed that US and the PEF induced conformational changes through partial unfolding and secondary structure remodeling from an α-helix to a β-sheet. Crystallographic and calorimetric determinations indicated decreased crystallinity and lowered thermal transition temperatures of the US- and PEF-modified FBPIs. Overall, non-thermal processing provided an effective strategy for upgrading FBPIs' functionality, with implications for developing competitive plant-based protein alternatives.

Use of hydration properties of proteins to understand their functionality and tailor texture of extruded plant-based meat analogues

Different protein sources create distinct textures in plant-based meat due to differences in their hydration properties when exposed to different time, temperature, and shear regimes, which in turn depend upon their solubility, protein structure, and specific amino acids. This research aimed to identify these differences and manipulate them to reach a desired texture utilizing simple and reproducible analytical methods to characterize protein properties as either cold or heat swelling. Protein functionality was determined through least gelation concentration (LGC), water absorption index (WAI), and rapid visco analysis (RVA). Cold swelling or CS proteins (pea protein isolate, soy protein isolate, Arcon S soy protein concentrate) were characterized by an LGC < 14% and/ or WAI > 4.0 g/g, while LGC > 16% and/ or WAI < 4.0 g/g indicates proteins with heat swelling or HS properties (Arcon F soy protein concentrate, wheat gluten, and fava protein concentrate). An RVA peak time of around or less than 3 min (<75°C peak temperature) indicated CS properties while greater than 3.5 min (>80°C peak temperature) was considered HS. Protein mixes or treatments comprising mainly of different combinations and ratios of CS proteins were hypothesized to create a softer textured vegetable protein product or texturized vegetable protein (TVP) and those based on HS proteins a firmer TVP. Bulk density was higher for HS treatments (274-287 g/L) than for CS treatments (160-223 g/L). CS treatments exhibited a microstructure that was porous, while HS showed a dense, laminar microstructure. Texture profile analysis showed that CS treatments seemed to show a lower hardness (1154-1595 g) than the HS treatments (1893-2231 g). PRACTICAL APPLICATION: Controlling texture can be a valuable tool when producing a plant-based meat product. Different applications have various texture requirements. For example, a plant-based fish stick would require a softer texture than a hamburger or chicken nugget. By increasing the knowledge of how protein functionality affects meat analogue texture, the time needed to produce new products with novel textures can be reduced. Money could also be saved by being able to quickly replace ingredients with a more affordable or accessible protein with similar swelling abilities to preserve product quality.

Antiproliferative and anti-inflammatory effects of fractionated crude lectins from boiled kidney beans (Phaseolus vulgaris)

In this study, we investigated the biological profile of lectins isolated from raw and boiled Japanese red Kintoki beans (red kidney beans [RKB]; Phaseolus vulgaris). Lectins in beans showing agglutination activity were retained after heating. Raw and boiled RKB lectins were fractionated using carboxymethyl- and diethylaminoethyl-Sepharose, respectively. Boiled RKB lectins were evaluated for carbohydrate specificity as well as cytokine-inducing and antiproliferative activities against cancer cells and compared with raw RKB lectins. Raw RKB lectins showed specificity for thyroglobulin and fetuin, whereas boiled lectins showed specificity for N-acetylneuraminic acid. Raw RKB lectins showed low resistance to proteases and tolerated temperatures greater than 80°C for 5 min. Notably, lectins from raw and boiled beans showed antiproliferative activity against five types of cancer cells B16, LM8, HeLa, HepG2, and Colo 679. In particular, lectins from raw beans exhibited a significantly stronger activity than those from boiled beans. Anti-inflammatory effects were notably observed in crude extracts from raw and boiled beans. Specifically, lectins fractionated from boiled beans markedly inhibited the expression of tumor necrosis factor-α and interleukin-6. Overall, our results showed that RKB lectins from boiled beans exert anti-inflammatory and anticancer effects and could be developed as potential chemopreventive agents. PRACTICAL APPLICATION: Japanese red kidney beans (RKB) are cultivated in numerous parts of the temperate zone and consumed in many countries. Lectins from boiled beans exhibited anticancer activity, similar to lectins from raw beans. Additionally, crude and fractionated lectins from boiled beans showed anti-inflammatory activity. Thus, boiled RKB lectins have the potential to be used as a bioactive protein for medical research and could be developed as anticancer agents.

O-GlcNAcylation: cellular physiology and therapeutic target for human diseases

O-linked-β-N-acetylglucosamine (O-GlcNAcylation) is a distinctive posttranslational protein modification involving the coordinated action of O-GlcNAc transferase and O-GlcNAcase, primarily targeting serine or threonine residues in various proteins. This modification impacts protein functionality, influencing stability, protein-protein interactions, and localization. Its interaction with other modifications such as phosphorylation and ubiquitination is becoming increasingly evident. Dysregulation of O-GlcNAcylation is associated with numerous human diseases, including diabetes, nervous system degeneration, and cancers. This review extensively explores the regulatory mechanisms of O-GlcNAcylation, its effects on cellular physiology, and its role in the pathogenesis of diseases. It examines the implications of aberrant O-GlcNAcylation in diabetes and tumorigenesis, highlighting novel insights into its potential role in cardiovascular diseases. The review also discusses the interplay of O-GlcNAcylation with other protein modifications and its impact on cell growth and metabolism. By synthesizing current research, this review elucidates the multifaceted roles of O-GlcNAcylation, providing a comprehensive reference for future studies. It underscores the potential of targeting the O-GlcNAcylation cycle in developing novel therapeutic strategies for various pathologies.

Effect of reduced crude protein diets supplemented with free limiting amino acids on body weight, carcass yield, and breast meat quality in broiler chickens

This study investigated the effect of reducing dietary crude protein (CP) content in the grower and finisher diets of broiler chickens on breast meat quality, muscle protein functionality, growth, carcass yield, and meat yield. To achieve this, a total of 1,269 one-day-old male Ross 308 chicks were fed 1 of 3 diets replicated 9 times each in a randomized complete block design with 9 blocks. The diets included a control (20.4% and 19.5% CP in the grower and finisher phase, respectively), a diet with a 1.5% reduction (CP-1.5%) and a diet with a 3.0% reduction (CP-3.0%) in CP content in both the grower and finisher phases. At the end of the experiment, the reduced-CP diets had no impact on body weight, feed intake, or feed conversion ratio. However, reduced-CP diet resulted in reduced (P < 0.001) total nitrogen intake (-7.46 and -11.94% in CP-1.5% and CP-3.0%, respectively). Breast meat quality was assessed (n = 36 birds/group), and the experimental diets were associated with a slightly increased (P = 0.07) ultimate pH (5.75, 5.79, and 5.81 for the control, CP-1.5%, and CP-3.0%, respectively). Breast fillets from the CP-1.5% and CP-3.0% groups had lower yellowness (b*, P < 0.001) and lower cooking loss (CL, P < 0.001) values than the control. Moreover, the solubility, emulsion activity, and stability indices of the sarcoplasmic and myofibrillar fractions of muscle proteins were not influenced by the diets. CP-1.5% and CP-3.0% diets were associated with an increased (P < 0.001) breast yield (18.39, 19.21, and 19.61% for the control, CP-1.5%, and CP-3.0%, respectively) while leg yield remained unchanged. Additionally, breast meat nutritional properties including protein and lipid contents were not impacted by the experimental diets. In conclusion, the CP content in the grower and finisher diets of broiler chickens can be reduced by as much as 3.0% without detrimental effects on performance or on meat quality as long as birds' amino acid requirements are adequately met.

Overview of the Incorporation of Legumes into New Food Options: An Approach on Versatility, Nutritional, Technological, and Sensory Quality

Consumers are more aware and demanding of healthy food options, besides being concerned with environment-friendly consumption. This paper aims to evaluate nutritional, technological, and sensory characteristics of legumes and their products' quality and versatility, considering potential applications in new food options. Legumes are foods that have a recognized nutritional group since they have high protein and fiber content. However, their consumption is still somehow limited for some reasons: in some countries it is not easy to find all the species or cultivars, they need an organization and planning before preparation since they need soaking, and there is the presence of antinutritional factors. Due to the different functionalities of legume proteins, they can be applied to a variety of foods and for different purposes, as grains themselves, aquafaba, extracts, flours, brans, and textured proteins and sprouts. These products have been inserted as ingredients in infant food formulations, gluten-free foods, vegetarian diets, and in hybrid products to reduce food costs as well. Foods such as bread, cakes, cookies, meat analogues, and other baked or cooked products have been elaborated with nutritional, technological and sensory quality. Further development of formulations focused on improving the quality of legume-based products is necessary because of their potential and protein quality.

Applications of Enzyme Technology to Enhance Transition to Plant Proteins: A Review

As the plant-based food market grows, demand for plant protein is also increasing. Proteins are a major component in foods and are key to developing desired structures and textures. Seed storage proteins are the main plant proteins in the human diet. They are abundant in, for example, legumes or defatted oilseeds, which makes them an excellent candidate to use in the development of novel plant-based foods. However, they often have low and inflexible functionalities, as in nature they are designed to remain densely packed and inert within cell walls until they are needed during germination. Enzymes are often used by the food industry, for example, in the production of cheese or beer, to modify ingredient properties. Although they currently have limited applications in plant proteins, interest in the area is exponentially increasing. The present review first considers the current state and potential of enzyme utilization related to plant proteins, including uses in protein extraction and post-extraction modifications. Then, relevant opportunities and challenges are critically discussed. The main challenges relate to the knowledge gap, the high cost of enzymes, and the complexity of plant proteins as substrates. The overall aim of this review is to increase awareness, highlight challenges, and explore ways to address them.

Aqueous phase extractable protein of wheat bran and germ for the production of liquid and semi-solid foods

To achieve a more sustainable global food production, a shift from animal to plant protein based food is necessary. At the same time, these plant proteins are preferentially derived from side-streams of industrial processes. Wheat bran and germ represent two major side-streams of the wheat milling industry, and contain aqueous-phase soluble proteins with a well-balanced amino acid composition. To successfully use wheat bran and germ proteins in novel plant-based liquid and semi-solid foods, they need to (i) be rendered extractable and (ii) contribute functionally to stabilizing the food system. Prior heat treatment and the occurrence of intact cell walls are important barriers in this regard. Several strategies have been applied to overcome these issues, including physical processing and (bio)chemical modification. We here present a comprehensive, critical overview of the aqueous-phase extraction of protein from (modified) wheat bran and germ. Moreover, we discuss the functionality of the extracted protein, specifically in the context of liquid (foam- and emulsion-type) and semi-solid (gel-type) food applications. In each section, we identify important knowledge gaps and highlight several future prospects that could further increase the application potential of wheat bran and germ proteins in the food industry.

Functional Properties of Brewer's Spent Grain Protein Isolate: The Missing Piece in the Plant Protein Portfolio

Plant protein sources, as a part of developing sustainable food systems, are currently of interest globally. Brewer's spent grain (BSG) is the most plentiful by-product of the brewing industry, representing ~85% of the total side streams produced. Although nutritionally dense, there are very few methods of upcycling these materials. High in protein, BSG can serve as an ideal raw material for protein isolate production. This study details the nutritional and functional characteristics of BSG protein isolate, EverPro, and compares these with the technological performance of the current gold standard plant protein isolates, pea and soy. The compositional characteristics are determined, including amino acid analysis, protein solubility, and protein profile among others. Related physical properties are determined, including foaming characteristics, emulsifying properties, zeta potential, surface hydrophobicity, and rheological properties. Regarding nutrition, EverPro meets or exceeds the requirement of each essential amino acid per g protein, with the exception of lysine, while pea and soy are deficient in methionine and cysteine. EverPro has a similar protein content to the pea and soy isolates, but far exceeds them in terms of protein solubility, with a protein solubility of ~100% compared to 22% and 52% for pea and soy isolates, respectively. This increased solubility, in turn, affects other functional properties; EverPro displays the highest foaming capacity and exhibits low sedimentation activity, while also possessing minimal gelation properties and low emulsion stabilising activity when compared to pea and soy isolates. This study outlines the functional and nutritional properties of EverPro, a brewer's spent grain protein, in comparison to commercial plant protein isolates, indicating the potential for the inclusion of new, sustainable plant-based protein sources in human nutrition, in particular dairy alternative applications.

Valorization of green biomass Azolla pinnata fern: multi-parameter evaluation of processing conditions on protein extractability and their influence on the physicochemical, structural, techno-functional properties and protein quality

BACKGROUND

This study determined the effect of processing conditions on protein extractability from Azolla pinnata fern, and their influence on the physicochemical, structural, techno-functional properties and protein quality.

RESULTS

The protein extraction from A. pinnata fern was optimized through response surface methodology obtaining a maximum yield of 18.93% with a recovery rate of 73.66%. The A. pinnata fern protein concentrate (AFPC) had five protein bands with a molecular weight ranging from 17 to 56 kDa. AFPC contained high β-sheet structure (36.61%), favouring its good thermal properties with three endothermic peaks at 54.28, 86.52 and 166.25 °C. The AFPC scored ≥ 1 for all essential amino acids, except for lysine and histidine. The AFPC exhibited exceptionally high techno-functional properties, particularly for water holding (5.46 g g^-1 ) and fat absorption capacity (10.08 g g^-1 ), and gelling properties (5% gelation concentration). The AFPC had high in vitro digestibility of 73%, signifying its high availability for human consumption.

CONCLUSION

The underexploited A. pinnata fern is a potential source of edible protein, thus a promising nutraceutical or ingredient of functional and health-promoting foods. © 2022 Society of Chemical Industry.

A comprehensive review on pulse protein fractionation and extraction: processes, functionality, and food applications

The increasing world population requires the production of nutrient-rich foods. Protein is an essential macronutrient for healthy individuals. Interest in using plant proteins in foods has increased in recent years due to their sustainability and nutritional benefits. Dry and wet protein fractionation methods have been developed to increase protein yield, purity, and functional and nutritional qualities. This review explores the recent developments in pretreatments and fractionation processes used for producing pulse protein concentrates and isolates. Functionality differences between pulse proteins obtained from different fractionation methods and the use of fractionated pulse proteins in different food applications are also critically reviewed. Pretreatment methods improve the de-hulling efficiency of seeds prior to fractionation. Research on wet fractionation methods focuses on improving sustainability and functionality of proteins while studies on dry methods focus on increasing protein yield and purity. Hybrid methods produced fractionated proteins with higher yield and purity while also improving protein functionality and process sustainability. Dry and hybrid fractionated proteins have comparable or superior functionalities relative to wet fractionated proteins. Pulse protein ingredients are successfully incorporated into various food formulations with notable changes in their sensory properties. Future studies could focus on optimizing the fractionation process, improving protein concentrate palatability, and optimizing formulations using pulse proteins.

Recent advances on the impact of novel non-thermal technologies on structure and functionality of plant proteins: A comprehensive review

The recent trend in consumption of plant-based protein over animal protein opens up a new avenue for sustainable agriculture practice, less environmental impact and greenhouse gas emission. The modification of plant-based proteins by novel non-thermal technologies includes the structural transformation followed by the modulation of their functional properties that are exploited to develop a protein ingredient system for application in food formulation. This review explores the impact of non-thermal process technologies on structural modification of plant proteins followed by improvement in protein's function in food formulation. Novel concepts articulating the impact of non-thermal technologies on structural and functional modification of plant proteins affecting it's digestibility and bioavailability are addressed. Limitations and prospects of applying non-thermal technologies in developing an alternative plant-based protein food system are also summarized. Non-thermal processes are considered as the emerging technologies that results in conformational changes in secondary, tertiary and quaternary structure of plant proteins which helps in modification of functional properties without jeopardizing the organoleptic properties and bioactivity of the protein. However, extensive future study is needed to optimize the non-thermal process parameters along with the finding of new protein sources to achieve healthy and sustainable plant-based food system.

Recent advances on characterization of protein oxidation in aquatic products: A comprehensive review

In addition to microbial spoilage and lipid peroxidation, protein oxidation is increasingly recognized as a major cause for quality deterioration of muscle-based foods. Although protein oxidation in muscle-based foods has attracted tremendous interest in the past decade, specific oxidative pathways and underlying mechanisms of protein oxidation in aquatic products remain largely unexplored. The present review covers the aspects of the origin and site-specific nature of protein oxidation, progress on the characterization of protein oxidation, oxidized proteins in aquatic products, and impact of protein oxidation on protein functionalities. Compared to meat protein oxidation, aquatic proteins demonstrate a less extent of oxidation on aromatic amino acids and are more susceptible to be indirectly oxidized by lipid peroxidation products. Different from traditional measurement of protein carbonyls and thiols, proteomics-based strategy better characterizes the targeted oxidation sites within proteins. The future trends using more robust and accurate targeted proteomics, such as parallel reaction monitoring strategy, to characterize protein oxidation in aquatic products are also given.

Effects of High Hydrostatic Pressure on Technical Functional Properties of Edible Insect Protein

The objective of this study was to determine the effects of high pressure to investigate the technical functional properties of the protein solution extracted from an edible insect, Protaetia brevitarsis seulensis. High pressure processing was performed at 0 (control), 100, 200, 300, 400, and 500 MPa at 35°C. The essential amino acid index of the control was lower (p<0.05) than that of the P. brevitarsis seulensis extract treated with 100 MPa. The SDS-PAGE patterns tended to become faint at approximately 75 kDa and thicker at approximately 37 KDa after high pressure treatment. The protein solubility and pH of the protein tended to increase as the hydrostatic pressure levels increased. The instrument color values (redness and yellowness) of the P. brevitarsis seulensis protein treated with high pressure were lower (p<0.05) than those of the control. The forming capacity of the protein solution with P. brevitarsis seulensis treated with high pressure was higher (p<0.05) than that of the control. In conclusion, we confirmed that the technical functional properties of edible insect proteins extracted under high pressure of 200 MPa are improved. Our results indicate that high pressure can improve the technical functional properties of proteins from edible insects.

Modification of pulse proteins for improved functionality and flavor profile: A comprehensive review

Consumers' preference to have a healthy eating pattern has led to an increasing demand for more nutrient-dense and healthier plant-based foods. Pulse proteins are exceptional quality ingredients with potential nutritional benefits, and might act as health-promoting agents for addressing the new-generation foods. However, the utilization of pulse protein in foods has been hampered by its relatively poor functionality and unpleasant flavor. Protein structure modification has been proved to be a useful means to improve the functionality and flavor profile of pulse protein. This paper begins with a brief introduction of hierarchical structure of pulse protein materials to better understand the structure characteristics. A comprehensive review is presented on the current techniques including chemical and enzymatic modifications and molecular breeding on pulse protein structure and functionality/flavor. The mechanism and the limitations and the toxicological concerns of these approaches are discussed. We conclude that understanding protein structure-functionality relationship is extremely valuable in tailoring proteins for specific functional outcomes and expanding the availability of pulse proteins. Furthermore, selective protein modification is a valuable in-depth toolkit for generating novel protein constructs with preferable functional attributes and flavor profiles. Innovative structure modification with special focus on the molecular basis for the exquisite protein designs is a pillar of pulse protein access to the desired functionality.

A review on protein extracts from sunflower cake: techno-functional properties and promising modification methods

De-oiled sunflower cake is a sustainable and promising protein source with high phenolic and fiber contents. The cake, which is an industrial by-product has been the subject of many studies investigating various aspects such as protein extraction, functional properties, interaction with other ingredients, and its performance in a wide range of food products. Innovative and conventional techniques of protein extraction from sunflower cake have been investigated to increase extraction yield and improve desired functional characteristics. Modulation of structure of plant-based proteins helps to control their techno-functional properties and widen their applications. Structure modification of proteins by physical methods including ultrasound treatment and gamma irradiation as well as enzymatic and chemical methods has been used to improve the functional properties of sunflower protein. This review collects and critically discusses the available information on techno-functional properties of protein extracts from sunflower cake and how its techno-functional properties can be tailored using various structure modification methods.

Functionality of bovine milk proteins and other factors in foaming properties of milk: a review

For many dairy products such as cappuccino-style beverages, the top foam layer determines the overall product quality (e.g. their appearance, texture, mouthfeel and coffee aroma release rate) and the consumer acceptance. Proteins in milk are excellent foaming agents, but the foaming properties of milk are greatly affected by several factors such as the protein content, ratio of caseins to whey proteins, casein micelle size, pH, minerals, proteolysis, presence of low molecular weight compounds (lipids and their hydrolyzed products) and high molecular weight compounds (polysaccharides); milk processing conditions (e.g. homogenization, heat treatment and aging); and foaming method and temperature. These factors either induce changes in the molecular structure, charge and surface activity of the milk proteins; or interfere and/or compete with milk proteins in the formation of highly viscoelastic film to stabilize the foam. Some factors affect the foamability while others determine the foam stability. In this review, functionality of milk proteins in the production and stabilization of liquid foam, under effects of these factors is comprehensively discussed. This will help to control the foaming process of milk on demand for a particular application, which still is difficult and challenging for researchers and the dairy industry.

High-Temperature Short-Time Preserves Human Milk's Bioactive Proteins and Their Function Better Than Pasteurization Techniques With Long Processing Times

Donor human milk is generally processed by holder pasteurization (HoP) at 62. 5°C for 30 min. This temperature-time combination is sufficient for eliminating pathogens in donor milk, but also negatively affects several bioactive milk components. Long heating up times may further affect the bioactive properties of pasteurized milk. High-Temperature-Short-Time (HTST), a treatment with shorter processing times (72°C for 15 sec), was investigated as a suitable alternative to HoP. In addition, pasteurization methods that follow the same temperature regime but with varying heating up times were compared. Human milk samples from four different donors were combined into one pool, which was then used to perform all analyses. The effects of these methods on the levels and functionality of immunoglobulin A, lactoferrin, lysozyme and bile salt-stimulated lipase, were evaluated with LC-MS/MS-based proteomics and activity assays, while the pasteurization efficacy was evaluated with an alkaline phosphatase test. HoP, a treatment with long processing times, times, caused the highest reduction in all proteins studied (reduced by 50-98%). Compounds such as lactoferrin and bile salt-stimulated lipase that are more sensitive to heat treatments were better retained with HTST, but their levels and functionality were still significantly lower than those of untreated donor milk (52 and 81% reduction of lactoferrin and bile salt-stimulated lipase activity, respectively). Our findings showed that a treatment with considerably shorter processing times, such as HTST, may reduce the thermal damage caused to the bioactive proteins compared to HoP, without affecting pasteurization efficacy. Since the vast majority of the donor human milk banks that are currently operating on a global level apply HoP to donor milk, our findings may provide relevant information for the optimization of donor milk processing.

Animal and Plant Protein Oxidation: Chemical and Functional Property Significance

Protein oxidation, a phenomenon that was not well recognized previously but now better understood, is a complex chemical process occurring ubiquitously in food systems and can be induced by processing treatments as well. While early research concentrated on muscle protein oxidation, later investigations included plant, milk, and egg proteins. The process of protein oxidation involves both radicals and nonradicals, and amino acid side chain groups are usually the site of initial oxidant attack which generates protein carbonyls, disulfide, dityrosine, and protein radicals. The ensuing alteration of protein conformational structures and formation of protein polymers and aggregates can result in significant changes in solubility and functionality, such as gelation, emulsification, foaming, and water-holding. Oxidant dose-dependent effects have been widely reported, i.e., mild-to-moderate oxidation may enhance the functionality while strong oxidation leads to insolubilization and functionality losses. Therefore, controlling the extent of protein oxidation in both animal and plant protein foods through oxidative and antioxidative strategies has been of wide interest in model system as well in in situ studies. This review presents a historical perspective of food protein oxidation research and provides an inclusive discussion of the impact of chemical and enzymatic oxidation on functional properties of meat, legume, cereal, dairy, and egg proteins based on the literature reports published in recent decades.

Modifying Faba Bean Protein Concentrate Using Dry Heat to Increase Water Holding Capacity

We investigated the effect of dry-heat treatment on the properties of faba bean protein concentrate using soy protein concentrate as a benchmark. While soy protein-widely used as an ingredient in meat replacers-is recovered through a wet fractionation, protein recovery from starch bearing pulses like faba bean can be done via dry fractionation. This process does not require drying or heating steps and therefore, keeps the original protein functionality intact. This results in differences in properties such as water binding capacity of the protein fraction. Faba bean protein concentrate was dry-heated at temperatures from 75-175 °C, which resulted in higher water-holding capacity and less soluble protein, approaching values of soy protein concentrate. These changes were due to partial denaturation of protein, changing the structure of the protein, and exposing hydrophobic sites. This led to protein aggregation, as observed by light microscopy. Only noncovalent bonds caused the decrease of solubility of dry-heated faba bean protein concentrate. We conclude that dry-heating of dry fractionated faba bean protein can change the functional properties of the protein fraction to desired properties for certain applications. The effect is similar to that on soy, but the underlying mechanisms differ.

Functional/physicochemical properties and oxidative stability of ground meat from broilers reared under different photoperiods

Long photoperiods are used in the broiler industry to maximize animal performance, though the impact on meat quality remains poorly understood. The current study evaluated the impact of photoperiod on functional/physicochemical properties and oxidative stability of meat through broiler processing. Ross 308 broilers (n = 432) were randomly assigned to 4 photoperiod treatments (hours in L = light, D = dark): 20L:4D, 18L:6D, 16L:8D, or 12L:12D with 6 pens per treatment. At 42 D of age, 2 broilers per pen (n = 12 per treatment) were harvested under standard conditions. Broiler tenderloin (M. Pectoralis minor) and leg muscles were removed at 1 D postmortem and frozen/stored at -40°C. After 24 h thawing at 2°C, the samples were deboned, ground, and formed into patties in 3 independent batches. Photoperiod had no impact on pH, water-holding capacity, textural profile, meat emulsion activity index, and thiol content (P > 0.05). The patties from 12L:12D and 16L:8D had lower CIE b∗ (yellowness) values than 18L:6D and 20L:4D (P < 0.05), whereas 12L:12D had lower chroma (color intensity) values than other treatments (P < 0.05). The meat from 20L:4D exhibited lower sarcoplasmic protein solubility than other treatments (P < 0.05), whereas both 20L:4D and 18L:6D exhibited lower total protein solubility than 12L:12D (P < 0.05). Higher transmission values (indication of protein denaturation) were observed in 20L:4D than in other treatments (P < 0.05), whereas 12L:12D also maintained lower values than both 18L:6D and 16L:8D (P < 0.05). There was an interaction (P < 0.05) between photoperiod and display storage on 2-thiobarbituric acid reactive substances values, where the patties from 12L:12D maintained less lipid oxidation compared with the patties from other treatments. Results of this study suggest photoperiod has limited impact on meat quality attributes, though rearing broilers with a 12L:12D lighting schedule may be beneficial in reducing protein denaturation and improving lipid stability.

Effect of enzyme-assisted hydrolysis on protein pattern, technofunctional, and sensory properties of lupin protein isolates using enzyme combinations

The modification of lupin protein isolates (LPI) by means of enzymatic hydrolysis (Lupinus angustifolius cultivar Boregine) was performed with four enzyme preparations (Alcalase 2.4 L, Papain, Corolase 7089, and Neutrase 0.8 L) in a one- and two-step process to determine the efficacy for the destruction of major IgE-reactive polypeptides and the evaluation of the technofunctional and sensory properties of lupin protein hydrolysates. Combinations of Alcalase 2.4 L and Papain were most effective in the degradation of polypeptides in L. angustifolius as measured by sodium dodecylsulfate-polyacrylamide gel electrophoresis. The enzymatic hydrolysis of the LPI increased their technofunctional properties such as protein solubility, foam activity, and emulsifying capacity almost independently of the enzyme preparation used. The sensory results showed a significant increase in bitterness from 1.9 for LPI to 5.7 for the combination of Alcalase 2.4 L and Papain in one-step process. The aroma attributes of the hydrolysates were very similar to untreated LPI. The results of this study show the possibility of enzymatic hydrolysis of LPI to destroy the major IgE-reactive polypeptides that increase the technofunctional properties of the isolates and thus their use in human nutrition as food ingredients.

Effect of spaghetti meat abnormality on broiler chicken breast meat composition and technological quality

The effects of spaghetti meat (SM) myopathy and sampling location on chicken breast meat physical traits, composition, and protein functionality were investigated using 30 normal (N) and 30 SM boneless fillets. Weight, drip loss, pH, and color traits were determined on intact fillets. Proximate composition, water holding capacity, mineral profile, SDS-PAGE, myofibrillar, and sarcoplasmic protein solubility, and emulsifying properties were assessed on both the superficial (S) and deep (D) layers of the breasts. SM fillets were heavier (P < 0.0001) and exhibited greater drip loss (P = 0.0131) and higher b* index on the skin side of the muscle (P < 0.0001). Muscle condition by layer interaction effect revealed that the superficial portion of SM fillets (SM-S) exhibited the highest moisture (P = 0.0003) and fat contents (P = 0.0011) coupled with the lowest protein (P < 0.0001) and ash contents (P = 0.0458). Total and soluble collagen amounts were higher in N-S and SM-S groups compared with N-D and SM-D (P < 0.0001). SM-S group exhibited the highest calcium (P = 0.0035) and sodium (P < 0.0001) levels. Overall, the myopathy had only minor impacts on protein profiles, while the muscle layer exerted a more remarkable effect. SM fillets exhibited higher pH but a lower myofibrillar protein solubility (P < 0.0001). Salt-induced water uptake, cooking loss, and final yield values suggested a potential impairment of water-holding capacity in SM-affected meat. Sarcoplasmic and myofibrillar emulsion activity indexes were similar between the 2 muscle conditions, but the stability of the emulsions was lower in SM meat. Overall, significant layer and muscle condition by layer effects were not observed in the functional properties of the breast meat. SM exerted a profound and negative impact on breast meat composition that led to detrimental consequences on functionality traits. Given the fundamental role of protein quality for meat processing, these data suggest that a further step toward the understanding of this myopathy should be the investigation of intrinsic protein characteristics.

Pulsed electric field and mild heating for milk processing: a review on recent advances

Pulsed electric field (PEF) treatment consists of exposing food to electrical fields between electrodes within a treatment chamber, which can improve the preservation of fresh-like products such as milk. Although several studies support the use of PEF technology to process milk at low temperature, these studies reported microbial reductions of around 3 log₁₀ cycles and also indicated a limited impact of PEF on some endogenous and microbial enzymes. This scenario indicates that increasing the impact of PEF on both enzymes and microorganisms remains a major challenge for this technology in milk processing. More recently, combining PEF with mild heating (below pasteurization condition) has been explored as an alternative processing technology to enhance the safety and to preserve the quality of fresh milk and milk products. Mild heating with PEF enhanced the safety of milk and derived products (3 log₁₀ -6 log₁₀ cycles reduction on microbial load and drastic impact on the activity enzymes related to quality decay). Moreover, with this approach, there was minimal impact on enzymes of technological and safety relevance, proteins, milk fat globules, and nutrients (particularly for vitamins) and improvements in the shelf-life of milk and selected derived products were obtained. Finally, further experiments should consider the use of milk processed by PEF with mild heating on cheese-making. The combined approach of PEF with mild heating to process milk and derived products is very promising. The characteristics of current PEF systems (which is being used at an industrial level in several countries) and their use in the liquid food industry, particularly for milk and some milk products, could advance towards this strategy. © 2019 Society of Chemical Industry.

Technical Functional Properties of Water- and Salt-soluble Proteins Extracted from Edible Insects

The amino acid composition, protein quality, and protein functionality of protein solution extracted from three edible insect species were investigated. We used 0.02% ascorbic acid and 0.58 M saline solution to extract water-soluble and salt-soluble proteins from the three insect species. Extracted protein solutions of Tenebrio molitor (TM), Allomyrina dichotoma (AD), and Protaetia brevitarsis seulensis (PB) were divided into six groups, according to species and solubility: WTM, WAD, WPB (water-soluble), and STM, SAD, and SPB (salt-soluble). Defatted TM had the highest protein content, but its protein solubility was the lowest, for both water and saline solutions. Amino acid composition differed by edible insect species and buffer type; SPB had the highest protein quality, followed by WPB. PB had a higher pH than the other species. Color values also differed among species. SPB had abundant high molecular weight proteins, compared with other treatments; and also had the highest foaming capacity, foam stability, and emulsifying capacity. In conclusion, PB is a good source of functional protein compared with the other studied species. Additionally, protein extraction using saline solution is promising as a useful method for improving edible insect protein functionality.

Comparison of raw meat quality and protein-gel properties of turkey breast fillets processed by traditional or cold-batter mincing technology

This study was conducted to evaluate the effects of cold batter mincing on meat quality and protein functionality, using turkey fillets that were chill-boned (CB) or hot-boned (HB) with crust-freeze-air-chilling (HB-¼CFAC) at -12°C. For each of four replications, 48 toms (male) were raised and processed at Michigan State University Poultry Farm and Meat Laboratory, respectively. After evisceration, the turkeys were subjected to one of the four treatments: (1) traditional mincing of CB fillets after water immersion chilling (WIC); (2) cold batter mincing of WIC, CB, quarter-sectioned (¼), and CB-¼CFAC; (3) traditional mincing of HB-¼CFAC fillets; and (4) cold batter mincing of HB-¼CFAC fillets. Before mincing, the pH and R-values of turkey fillets in HB-¼CFAC were higher and lower, respectively, than those in CB fillets. During cold-batter mixing, the initial batter temperatures at -1.5 to -2.1°C reached 1.5°C and 14°C at 6 and 12 min, respectively, and ended at 26 to 31°C at 24 min. During traditional mincing, the initial batter temperatures at 3 to 4°C increased by ∼10°C every 6 min, and ended at 32 to 35°C with higher batter temperatures seen for the 2% salt than the 1% salt batter. Dynamic rheological properties indicated that the cold-batter mincing showed elevated G' compared to the batters of traditional mincing, regardless of mixing time, indicating that the gel-setting temperature was reduced in the cold-batter mincing, potentially due to the different amounts of extracted protein and structural change. After cooking, improved cooking yield and protein functionality were observed in the batter of HB-¼CFAC fillets than the batter of CB fillets as well as in the batter of 2% salt than the batter 1% salt (P < 0.05). These results indicated that HB-¼CFAC fillets produced superior raw meat quality over the CB fillets, and cold batter mincing of HB-¼CFAC fillets significantly improved protein functionality compared with the traditional mincing of CB fillets (P < 0.05).

Potential of recovered proteins from invasive green crabs (Carcinus maenas) as a functional food ingredient

BACKGROUND

Invasive green crabs contain high-quality proteins that have potential as functional ingredients in formulated foods. This study evaluated the functional properties and compositional characteristics of green crab proteins recovered by isoelectric solubilization/precipitation (ISP).

RESULTS

Mechanically separated green crab mince (control) was solubilized at pH 2 (PP2) and pH 10 (PP10), then proteins were precipitated at pH 5.5 and subsequently dried. Yield of recovered protein powder was approximately 1.5 times higher for PP2 than for PP10. Compared with the control (230 g kg^-1 ), ash content was reduced in PP2 (54 g kg^-1 ) and PP10 (23 g kg^-1 ) samples. PP2 contained predominantly large-molecular-weight proteins, while small-molecular-weight proteins were distributed in PP10. With regard to functional properties, at pH 7 and 8, solubility of PP10 was significantly higher than that of PP2. At pH 7.5, PP10 exhibited significantly higher emulsifying activity (1482 m² g^-1 ) than PP2 (858 m² g^-1 ) and the control (958 m² g^-1 ). PP2 showed statistically higher gelation activity and had higher L* value than PP10 and the control.

CONCLUSION

The results indicate that recovered green crab proteins have functional properties potentially useful for formulated foods, and that these functional properties can be modified by the solubilization pH during the recovery process. © 2018 Society of Chemical Industry.

Extraction, composition, and functional properties of dried alfalfa (Medicago sativa L.) leaf protein

BACKGROUND

Alfalfa is considered a potential feedstock for biofuels; co-products with value-added uses would enhance process viability. This work evaluated dried alfalfa leaves for protein production and describes the functional properties of the protein.

RESULTS

Dried alfalfa leaves contained 260 g kg^-1 dry basis (DB) crude protein, with albumins being the major fraction (260 g kg^-1 of total protein). Alkali solubilization for 2 h at 50 °C, acid precipitation, dialysis, and freeze-drying produced a protein concentrate (600 g kg^-1 DB crude protein). Alfalfa leaf protein concentrate showed moderate solubility (maximum 500 g kg^-1 soluble protein from pH 5.5 to 10), excellent emulsifying properties (activity 158-219 m²  g^-1 protein, stability 17-49 min) and minimal loss of solubility during heating at pH ≥ 7.0.

CONCLUSIONS

It is technically feasible to extract protein with desirable emulsifying and heat stability properties from dried alfalfa leaves; however, the dried form may not be a practical starting material for protein production, given the difficulty of achieving high yields and high-purity protein product. © 2016 Society of Chemical Industry.

Protein functionality of concentrates prepared from yellowfin tuna (Thunnus albacares) roe by cook-dried process

Three kinds of roe protein concentrates (RPCs: boil-dried concentrate, BDC; steam-dried concentrate, SDC; freeze-dried concentrate, FDC) were prepared from yellowfin tuna to produce value added products for food applications. The buffer capacities of the RPCs were higher under alkaline than under acidic conditions. The water holding capacities of the RPCs were in range 4.5-4.7 g/g protein at pH 6.0. The protein solubility of the FDC (14.2%) was higher than those of the BDC (5.4%) and SDC (5.5%) at pH 6.0. The foaming capacity of the FDC (156.8%) was higher than those of the BDC (109.7%) and SDC (109.4%); the FDC foam was stable for 60 min. The oil-in-water emulsifying activity index of the FDC (12.2m2/g protein) exceeded those of the BDC and SDC (2.2m2/g protein). Protein concentrates from yellowfin tuna roe may be useful as a potential protein source and as a high-value food ingredient.

Comparative study of the functional properties of lupin, green pea, fava bean, hemp, and buckwheat flours as affected by pH

The demand for products of high nutritional value from sustainable sources is growing rapidly in the global food market. In this study, the effect of pH on the functional properties of lupin, green pea, fava bean, hemp, and buckwheat flours was investigated and compared with wheat flour. Functional properties included solubility, emulsifying and foaming properties, gelling ability, and water holding capacity (WHC). All flours had minimal solubility at pH 4 and their corresponding values increased with increasing pH. Emulsifying properties were improved at pH 10 for all samples and emulsion stability showed a similar trend. Increasing pH in the range 4-10 enhanced the foaming properties of the flours, particularly buckwheat and hemp. Wheat, green pea, buckwheat, and fava bean were more capable of forming firm gels compared with lupin and hemp, as indicated by least gelling concentrations (LGCs). The ranking of the water binding properties of the different types of flours were lupin>hemp>fava bean>buckwheat>green pea>wheat. Results indicate that underutilized flours from sustainable plant sources could be exploited by the food industry as functional food ingredients or as replacements of wheat flour for various food applications. Depending on the application, flour functionality may be effectively tailored by pH adjustment.

Cold-batter mincing of hot-boned and crust-freezing air-chilled turkey breast improved meat turnover time and product quality

The purpose of this research was to evaluate the combined effects of turkey hot-boning and cold-batter mincing technology on acceleration of meat turnover and meat quality improvement. For each of 3 replications, 15 turkeys were slaughtered and eviscerated. Three of the eviscerated carcasses were randomly assigned to water-immersion chilling for chill-boning (CB) and the remaining were immediately hot-boned (HB), half of which were used without chilling whereas the remaining were subjected to crust-freezing air chilling (CFAC) in an air-freezing room (1.0 m/s, -12°C) with/without 1/4; sectioning (HB-1/4;CFAC, HB-CFAC). As a result, CB and HB breasts were minced using 1 of 5 treatments: (1) CB and traditional mincing (CB-T), (2) HB and mincing with no chilling (HB-NC), (3) HB and mincing with CO2 (HB-CO2), (4) HB and mincing after CFAC (HB-CFAC), and (5) HB and mincing after quarter sectioning and CFAC (HB-1/4;CFAC). Traditional water-immersion chilling took an average of 5.5 h to reduce the breast temperature to 4°C, whereas HB-CFAC and HB-1/4;CFAC took 1.5 and 1 h, respectively. The breast of HB-CFAC and HB-1/4;CFAC showed significantly higher pH (6.0-6.1), higher fragmentation index (196-198), and lower R-value (1.0-1.1; P < 0.05) than those of the CB controls. No significant differences (P > 0.05) in sarcomere length were seen between CB-T and HB-CFAC filets regardless of quarter sectioning. When muscle was minced, the batter pH (5.9) of CB-T was significantly lower (P < 0.05) than those (6.1-6.3) of HB-NC, HB-CO2, and HB-1/4;CFAC, with the intermediate pH (6.0) seen for the HB-CFAC. When meat batters were cooked, higher cooking yield (90 - 91%; P < 0.05) was found in HB-CFAC, HB-1/4;CFAC, and HB-CO2, followed by HB-NC (90%) and finally CB-T (86%). Stress values (47-51 kPa) of HB-CFAC gels were significantly higher (P < 0.05) than those of CB-T (30 kPa) and HB-NC (36 kPa). A similar trend was found in strain values.